This paper describes experimental studies of cutting the outer layer of onions in a machine processing process. For this purpose, an original, globally innovative machine design with a modular structure was used, which was constructed in a real scale. For the purposes of carrying out the experimental studies, a test stand was constructed, a plan and programme for the studies were adopted, and a research methodology was developed. The results gained and the data obtained from the equations of the regression function for the developed machine design were used to construct systems of independent variables for which the dependent variable reaches extreme values. The unit energy consumption of the onion peeling process increases together with an increase in the number of air nozzles and the air pressure supplying the unit for removing the skins, while an increase in the material feeding speed and in the distance of the air nozzles results in a decrease in the energy consumption of the process.